From newbie to newbie: Deleting objects from an Age

[Chacal]

------------- NOTE --------------------------------------
This was written for PyPrp 0.5. The import function
is no longer supported in newer versions. You can
install 0.5 for this tutorial, or you can bypass the
Blender part entirely as explained below.
------------- NOTE ---------------------------------------
This tutorial uses Blender to explain the concepts.
However, if you just want to unlock your relto, this
is not necessary. You can bypass all parts marked
as OPTIONAL and just delete the objects.
-------------------------------------------------------------

Today I picked up where I stopped in 2005 and spent the day exploring Cyan Ages using Blender and other tools (the alternative was doing serious work on a Sunday).

I had some success which will seem trivial to old hands, but I thought I could help other newbies by sharing what I found, as a clever way to introduce some basic concepts. This could start a new "From newbie to newbie" series of tutorials. I'm starting by deleting objects because it's easier.

Feel free to comment, if this is worthless I can always delete it.

[Chacal]

This tutorial will demonstrate how to delete objects from a Cyan Age in single-player Uru.
This will not work for Uru Live!

I don't know about you but when Cyan said Relto was to be my personal Age, I took that very seriously. So it has always annoyed me that I couldn't go wherever I wanted on my own personal Age. Right next to the hut there is a path leading to the rocky point where the rocket was in Myst. For some reason, the developers decided they didn't want us to go there so they blocked the way. Feeling around, it is possible to discover the shape of an invisible object that blocks our way (a collision mesh). Also, the 3rd-person camera movement is restricted in this area. There is another such invisible wall near the waterfall, that prevents us from going around the mountain.

Presently there are two ways to go past these walls: in flymode, and by using a convoluted sequence of movements known as "Relto climbing", which may or may not work depending on your skill with the mouse and the performance of your PC (it also works in MOUL).

Not good enough. I want to walk wherever I want (what part of "Personal Age" doesn't Cyan understand?), so let's remove the stupid wall. This is not as simple as it sounds because currently (november 2007) it is not possible to modify a Cyan Age in Blender and export it back to Uru. Several things will be missing and the Age won't work. We will need to use several different tools to do the job.

The steps will be:
0- Preparation
1- Find the objects
2- Delete the objects
3- Recalculate the checksum

0- Preparation
0.1 Backup the Uru file(s)
It is essential to keep an untouched backup of your Uru installation. I just copied the entire "Uru - Ages beyond Myst" folder to a different disk before modifying anything ( using Drizzle, installing off-line KI or any fan Age). For this tutorial, you need to backup two files named "Personal_District_psnlMYSTII.prp" and "Personal.sum" in the "dat" subdirectory.

0.2 Download and install PlasmaShop 3.x (including PrpShop) by Zrax
See instructions and download link here:
viewtopic.php?f=86&t=2639

0.3 OPTIONAL: Download and install Blender, the PRP plugin and other supporting items.
See the current list at http://guildofwriters.com/wiki/Installing_PyPRP

1- Find the objects (optional)

1.1 Start Blender and import your Relto

Make a window into a scripts window. Use Scripts / Import / Pyprp / Single prp. Browse to the working directory you created in step 0.2 and select "Personal_District_psnlMYSTII.prp". Click on "Import .prp". The import process takes around 5 minutes on my P4- 2Ghz. Check the Blender console for activity, an insane amount of text should zip by. A successful import ends with "done in xxx seconds".

Make a window into a 3D view, and manipulate the view until you get something that looks like this:

[Chacal]

To make working easier, let's get the skyboxes and cloud layers out of the way.
- In the 3D view, select the huge sky bubble. Hit the "M" key and click on one of the 20 layer buttons, for example button 11 on the lower row. This will move the object in layer 11. By not activating layer 11 in the 3D view, we can prevent this object from blocking our view.
- Do the same for another object that blocks the view: CameraClouds

Now let's find the darn invisible.

Looking around, we find an interesting object: "IslandWallCollision". The name is pretty self-explanatory. It goes all around the hut, the path and the mountain, exactly the shape of the "invisible wall" we felt in the game. It stops short at left, which explains why the published "Relto climbing" trick, in which you have to jump to a small island and then on the ground past the edge of the invisible wall, works. Let's take that name down. Another interesting object is "CamAvatarBlocker". It also seems to be a part of the invisible wall. Let's take that name down too. Figure 2 shows both objects selected.

Note: It must be understood that we're not just deleting objects at random. I have spent a few hours examining the whole Age and the relationship between objects, and doing tests, before settling on those two particular objects. That's why we took a backup. This particular case was easy because the two collision objects had no other function. In many other Ages, such as the City, collision objects are more complex and make up walls and floors. Removing them would make your avatar go through the floor and panic-link to Relto.

[Chacal]

This is enough for the avatar movements, but we also want to get rid of the restriction on camera movement. Looking around, we find a region called "Box01" (figure 3), which seems to fit with our in-game observation: as soon as the avatar enters this region, the camera switches to a fixed position ("treeBlockedCamera"). We'll get rid of Box1 too so let's take that third name down. Incidentally, we just learned how a simple camera region works.

We can now exit Blender without saving, as we don't want to modify the file in Blender.

[Chacal]

2- Delete the objects

We will now use PrpShop to delete the three objects we have found: "IslandWallCollision", "CamAvatarBlocker" and "Box01".

2.1 Start PlasmaShop 3.x.
If you have not set it up yet for use with your Uru game, do so by selecting Game: Edit games list, Add, and tell it where to find the Uru files.
Select your game in the list and folders should now appear in the file browser window at left.

2.2 In the file browser window, open "Personal", then double-click on "District_psnlMYSTII.prp". This will launch PrpShop in a new window (Figure 4).

Figure 4: PrpShop

Tutorial_delete_col_prp01.jpg (94.36 KiB) Viewed 8629 times

2.3 In PrpShop, open "Personal", "psnlMYSTII", "Generic Physical(PX, HK, ODE)", scroll down to "IslandWallCollision". Right-click on it, select "Delete". Gone!

2.4 Do the same for "CamAvatarBlocker" and "Box01".

2.5 Save the prp file using either the disk icon, the File/Save menu option, or Ctrl-S. We can now close PrpShop.

[Chacal]

3- Remove the checksum

Our PRP file has been changed and it no longer matches the checksum in Personal.sum. Uru will think our Age is corrupted and will complain loudly and refuse to start. Fortunately, checksums are not mandatory, so the easiest fix is to just delete them.

3.1 In PlasmaShop, open "Ages", "Personal", then double-click on "Personal.sum". A window opens in the right pane, with 3 columns: Filename, Timestamp and MD5 (see Figure 5). If there is nothing else in the window, your checksums are already deleted and there is nothing more to do. Go to step 3.4.

Figure 5: Personal.sum selected in PlasmaShop

Tutorial_delete_col_sum01.jpg (120.78 KiB) Viewed 8629 times

3.2 Otherwise select "dat\Personal_District_psnlMYSTII.prp" in the right pane, richt-click and select "Remove". You can also select the other checksums and remove them if you wish.

3.3 Save the checksum file using either the disk icon, the File/Save menu option, or Ctrl-S.

3.4 We can now close PlasmaShop and try our changes in Uru.

[Chacal]

Done!

If all went well, we can now launch Uru and link to Relto. If not, we will have to restore our "Personal_District_psnlMYSTII.prp" and "Personal.sum" backup files and start again.

Note that because we have changed a file, we must start Uru by using Uru.exe, not UruExplorer.

We are now able to walk all the way to the end of the path, and around the mountain. The camera follows obediently. There is even a way we can climb our mountain!

NOW it's my personal Age.

[mar]

Whoow Chacal, that's a very good and usefull tutortial.

I never have had the courage to experiment with this thinks, it is all "magic"to me. My skills are not enough at that point and expirement with it cost me lots of time with I not have.
But now it is a other matter. I can follow your tutortial and see how all that "magic"stuff works and maybe I can use it in my a age.

Thanks a lot I think a world is going open for me.

Mar

[Chacal]

Good luck, and don't forget step 0.1.

[mar]

Hi Chacal,

I have made it, I walked around my hut.

For a second time it is a very clear tutortial.
Further it is fun to see " the making of" how Cyan did some kind of things .
It give a lot of inside information. I am waiting with curiousity to your next tutortial about this kind of things.

PS I have backup and save files for I started

Mar